Parking garage height sensors lie — trucks and SUVs scrape roofs after 'clearance OK' lights

Many parking garages display a green 'clearance OK' light at the entrance based on a single overhead sensor, but the actual clearance drops by 6-12 inches deeper inside due to hanging pipes, sprinkler heads, and sloped ramps between levels. Drivers of full-size trucks and SUVs enter confidently, then hear the sickening crunch of their roof rack or cargo box hitting infrastructure two turns in. Insurance typically denies these claims as driver negligence, and the garage operator's posted signage ('enter at your own risk') shields them from liability. This persists because garage operators measure clearance at the entrance beam only and have no financial incentive to map internal obstructions, while retrofitting variable-height sensors throughout the structure costs $50K+ that generates zero additional revenue.